1. Field of the Invention
The present invention relates generally to a work finishing machine, and more particularly to a machine of the type that includes gyratory shafts for holding individual workpieces for the purpose of polishing the surfaces and edges of the workpieces together with their abrasive media within the individual containers. More specifically, it relates to an improvement in the construction of the gyratory shafts for holding workpieces for use in the machine of the above type.
2. Description of the Prior Art
A conventional prior art machine of the class disclosed herein, such as U.S. Pat. No. 4,373,296, includes individual gyratory shafts for holding individual workpieces, and the axial rotation of those gyratory shafts is caused by means of the combination of a drive motor and a power transmission system. The gyratory shafts have one-way rotation and a fixed constant speed.
The drive motor and power transmission combination includes no control means that causes a change in the speed of rotation during one complete revolution of the gyratory shafts. The reversal of the direction of rotation for the gyratory shafts must be accomplished by varying the direction of rotation for the drive motor. In this way, it is very difficult to obtain the reversal of the shafts at very short intervals. Furthermore, when a given gyratory shaft is to be stopped in position for attaching a workpieces thereto, a device is provided for controlling the position in which the given gyratory shaft is to be stopped. In this case, it is necessary to determine the relative position between the work tightening device and the work charging device so that their positions can match each other.